The mechanisms involved in the biosynthesis of the adenohypophysial glycoprotein hormones Luteinizing Hormone and Follicle-Stimulating Hormone have not yet been delineated. Studies on the biosynthesis of these gonadotropins have dealt mainly with regulation of synthesis and are confined to the organ level. The experiments herein propose to study the biosynthesis of the gonadotropins at the subcellular level. In particular, these experiments propose to examine the events which occur between the synthesis of precursor peptide chains and the secretion of native hormones. Specifically, it is proposed to: 1. determine the earliest synthetic forms of the gonadotropins, individual subunits or prohormones, 2. to determine what forms are glycosylated and to what degree; 3. to determine the subcellular location where the subunits combine or where the prohormones are cleaved; 4. to identify the subcellular organelles involved in glycosylation; and 5. to determine if the forms of the hormones found in secretory granules are the ones which are secreted.